1 Department of Microbiology, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong (SAR), People's Republic of China.
2 Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore.
3 Public Health Laboratory, Faculty of Medicine, University of Birmingham, Birmingham, UK.
4 Department of Microbiology, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong (SAR), People's Republic of China margaretip@cuhk.edu.hk.
5 Shenzhen Research institute, The Chinese University of Hong Kong, Shenzhen, People's Republic of China.